Miniature lamp instrument illuminator system



Aug. 29, 1939. P. KOLLSMAN MINIATURE DAMP INSTRUMENT ILLUMINATOR SYSTEM Filed Oct. '15, 1937 2 SheetsSheet 1 INVENTOR PH L KDLLSMHN Aug. 29, 1939. P. KOLLSMAN MINIATURE LAMP INSTRUMENT ILLUMINATOR SYSTEM Filed OOL. 15, 1937 2 Sheets-Sheet 2 a INVENTOR I UL KULLfiMFIN Ma A$T3RNEY V |& PM.

Patented Aug. 29, 1939 MINIATURE LA INSTRUMENT? ILLUMINA'EOR SYSTEM Paul Kolllsman, Stamford, Conn.

Application October 15, 1937, Serial No. 169,121

5 Claims.

This invention relates to electric illuminating means, and especially to a lamp, base and socket combination which is particularly adapted 'to utilization with an indicating instrument, and to easy removal and replacement of the lamp member from the front of the instrument under difficultoperating conditions.

In the illumination of indicating instruments, particularly airplane instruments, it has been found convenient to provide a cover glass or sight glass for the instrument, with white paint or diffusing. means at the edge of the glass over most of its periphery, and to provide adjacent one point in the periphery, a very small miniature lamp, which, by radiating into the exposed edge of the glass, delivers light to the diffusing means adjacent the edges of the glass cover plate, from which it is thrown'onto the scale graduations and pointer.

Great diiliculty has, however, been experienced in obtaining a lamp and socket combination which is sufficiently small to avoid interference with the various instruments; which will stay firmly in place in spite of the extreme vibration encountered in airplanes; and which can be readily changed when it burns out, with a minimum of difiiculty and a minimum of interference with other instrument parts, and which can be changed easily enough to permit the user to make the change while in flight.

Thus, the problem requires that the lamp shall be extremely small; that it shall be replaceable from the front of the instrument; that it shall be held firmly in place, and that it shall have members which are readily grasped by the operators fingers to remove and replace the lamp.

The present invention provides a socket, a base cooperating therewith and a miniature lamp held therein, which is readily inserted and removed from the front of the instrument, into illuminating relationship with the edge of the glass sight window of the instrument.

The present invention is an improvement over the instrument shown in Patent No. Re. 20,937, (and is a continuation in part of my applications for patent, Serial No. 719,115 and Serial No. 53,972).

Thus, an object of the invention is to provide for the removable and replaceable mounting of a miniature incandescent electric light bulb in a socket, through the length of which the bulb passes during the removal and replacement.

A further object of the invention is to pass a miniature lamp bulb through the length of a supporting socket and to anchor it therein while making electric connection thereto.

A further object of the invention is to remove and replace a lamp base by manipulation of a vfinger grip portion while passing the lamp bulb through a supporting socket.

(Cl. 176-32) 7 Still another object of the invention is to pass a. lamp bulb through a socket member into illuminating relationship with an object and lock the lamp in position by a bayonet joint system.

Still a further object of the invention is to pass a lamp bulb through a socket into illuminating position and hold it therein by the interrelationship of contact pins and latch springs.

Yet another object of the invention is to support a lamp bulb in a rectangular base, pass the bulb through a rectangular socket, and lock the rectangular base within the rectangular socket.

Still another object of the invention is to support a lamp in a socket, and make electric contact thereto by means of pairs of rotatable switch blade type of contact-making lock members.

Still another object of the invention is to pass a lamp bulb through a socket, into illuminating position with respect to an instrument dial, to hold the lamp in illuminating position by the application of a locking member, and to eject the lamp from the socket by a contact spring upon removal of the locking member.

Still a further object of the invention is to pass a lamp bulb through a socket, lock it therein, and make electric contact thereto through a. ferrule adjacent one end of the lamp bulb, and a tip contact at the other end of the lamp bulb.

Other objects and structural details will be apparent from the following description when read in connection with the accompanying drawings, wherein Fig. 1 is a side view, partly in section, of a lamp, a lamp base, and socket combination utilizing a bayonet joint type of lock;

Fig. 2 is a top view of the socket of the embodiment of Fig. 1;

Fig. 3 is a bottom view of the lamp and base members of the embodiment of Fig. 1;

Fig. 4 is a detailed view of the locking members of the socket of Fig. 1;

Fig. 5 is a side view, partly in section. of a socket, lamp and lamp base combination utilizing spring grip members for holding the lamp and lamp base therein and making electric connection thereto;

Fig. 6 is a top view of the socket member of the embodiment of Fig. 5;

Fig. '7 is a bottom view of the lamp and base members of the embodiment of Fig. 5;

Fig. 8 is a top view of a square socket utilizing spring clip members;

Fig. 9 is a bottom view of a lamp and square base member adapted to cooperate with the socket of Fig. 8;

alternative form of socket, base and lamp bulb in which the connection to the filament is made between opposite ends of the bulb.

Referring to Figs. 1, 2, 3 and 4, which show a preferred embodiment of the invention, the lamp member I is mounted, preferably by cementing or by friction grip or other supporting means as desired, in a tubular insulating material base 2, which has a finger grip portion 3 which may be knurled or smooth, as desired.

The base portion 2 is provided with contact pins 4. The socket member 6 may conveniently be made as part of an airplane instrument case member 5, as shown, and it is desirably positioned at an edge of the instrument, above and adjacent to the sight glass window 7. The window 1 has a cooperating light chamber interposed between the socket and the glass and has adjacent its edge a diffusing medium 8, such as a coating of white paint or a ring of frosted aluminum, in either event the diffusing medium being omitted over a short portion of the glass 1 adjacent the socket 6. Bayonet joint slots 9 in the socket member 6 are provided, adjacent to lock spring members II which are connected to the respective electric power supply means.

For airplane instrument service the bulb I may conveniently have a diameter of approximately 4; inch, the base portion 2 may conveniently have a diameter of approximately A; inch, and the finger grip portion 3 may conveniently have a diameter of approximately inch.

In the operation of this device, the lamp memher 2 is entered into the socket 6 from the front of the instrument, and then the base portion 2 follows into the socket 6, thereby carrying the bulb member I through the socket into illuminating relationship with the edge of the glass I, the pins 4 being passed down the bayonet slots 9. The finger grip portion 3 is then given a small amount of rotation which carries the pins 4 under the contact locking springs ll, thereby holding the base and lamp firmly in the socket and simultaneously making electric contact for the energization of the lamp filament. As will be obvious, this procedure is readily conducted by an operator wearing heavy gloves in spite of the small size of the members utilized, because of the extreme simplicity of the construction and of the movements required. Thus, this illuminating means cooperates readily with an airplane instrument for the illumination of the dial and pointer thereof to provide a highly efll cient lighting system. It is to be noted that the instrument is desirably equipped with a black dial having white graduations and numbers and a white pointer. By this construction, only a minimum of total light flux radiates from the instrument to the observers eye, and the contrast between the black dial and the illuminated scale and pointer is sufliciently high to make the scale and pointer readily readable without reducing the users visual acuity when his eyes are dark adapted, as during night flying. In addition, the lamp and socket are extremely small; do not add objectionably to the size of the instrument, and, in addition, the lamp portion is very readily removed and replaced when desired for such reasons as a burned out bulb; and the necessary electric connections are automatically made by the mere operation of inserting the bulb' and base into the socket, which operation is conducted wholly from the front or exposed face of the instrument.

Another desirable and preferred embodiment of the invention is shown in Figs. 5, 6 and 7. This embodiment is particularly convenient and desirable because of the fact that it does not require any twisting of the bulb or base during insertion of the lamp. As shown in these figures, a bulb 2| is provided which is attached,

preferably by cementing, in a base member 22 for the admission of the contact pins 24, and

spring members 3| are provided below the entrance slots 29. The spring members have curved tops and locking depressions 32, as shown in Fig. 5, into which the pins 24 enter, and the depressions 32 are shaped to provide a snug grip which is resistant to vibrations, but which will release the pins 24 when a substantial outward pull is applied to the finger grip member 23.

In the first described embodiment the pins 4 may conveniently have flat ends to minimize the space required but in the embodiment of Figs. 5, 6 and '7 the pins 24 preferably have rounded ends to make a more satisfactory engagement with the depressions 32 in the springs 3|, since a more satisfactory holding and a. superior engaging and disengaging action is thereby attained.

In operation, the lamp, bulb and base are inserted into the socket into illuminating relationship with the glass cover plate 21 and the lamp member is passed entirely through the socket into a light chamber adjacent the glass 21 in the same manner as occurs in the previously described embodiment and are held therein by engagement between the springs 31 and pins 24, which simultaneously make the necessary electric contact for supplying power to the filament. Thus, this embodiment performs broadly, the same functions as the previously described embodiment, with the additional advantage that no rotation of the base and bulb is required for locking the lamp in place.

Another desirable embodiment is shown in Figs. 8 and 9, which embodiment is in general closely similar to the previously described embodiments. A similar lamp 4| is cemented intoa base 42, which base is provided with a finger grip portion 43 and locking pins 44, to which electrical connection is made from the respective ends of the filament of the lamp 4|. The base member 42 and finger grip portion 43 are square in plan rather than circular as in the previously described embodiments. The socket member 46 is desirably made as an integral part of the instrument case 45, and is also square in form. A sight glass 4! and diffusing medium 48 are provided as in previous instances. Slots 49 are provided for the entrance of the pins 44 and contact springs 5|, closely similar to the contact springs 3|, are also provided with depressions similar to the depressions 32.

This embodiment operates in a manner closely similar to the second described embodiment with the still further advantage that the base can not be rotated after a partial insertion into the socket. When the base is once inserted, with the pins on the proper sides, the further entry,

locking in place, and completing of the electrical 75 filament is connected to the tip' contact I25 carconnections, occurswithout further action other than a straight inward push upon the finger grip portion 43.

Still another desirable embodiment of the invention is shown in Fig. 10 in which a lamp bulb IOI is cemented within a base member I02 which has a finger grip portion I03. Attached to the underside of the base member I02 are spring grip members I04 which are connected respectively to the ends of the filament within the bulb I0i. integral part of the case member I05 in suitable relationship to the sight glass I01 and the diiiusing member I08. Attached within the socket I06 are spring grip members I00, as is particularly well shown in Fig. 11. The members I09 are connected to .the respective'treminals of the current supply and with the members I04 serve as circuit leads and locking membersto hold the lamp in place.

In this embodiment of the invention, the base I02 may be grasped by its finger grip portion I03 and inserted into the socket I06 carrying the .bulb IOI into and through the socket into an illuminating relationship with the sight glass I01 and thereafter may be given a partial rotation to engage the free ends of the members I04 under the free ends of the members I09, whereatter the lamp is heldfirmly in place by the spring grip occurring therebetween. This embodiment provides the advantages of the previously described embodiments, and in addition the further advantage that the lamp and base are very solidly held in place with circuit connecting means which will carry a relatively ,large amount of current without heating or an undue voltage drop in the contact surfaces.

Still another embodiment of the invention is shown in Fig. 12, in which the lamp bulb I2I is shown mounted in a base member I22 which may be of insulating material which may be threaded, or may be equipped with bayonet type locking pins and may have afinger grip portion I23 attached thereto. A metallic ferrule I24 is provided around the lamp I2l attached to the base member I22 with one terminal of the filament connected thereto. The other terminal of the ried upon the outer end of the bulb I2I. The socket I20 is desirably made as an integralpart of the instrument case as in the previously described embodiments, and is positioned in proper relationship to the sight window glass. Within the socket I20 there is provided a screw thread I21 or bayonet locking slots as before described, adapted to cooperate with the thread or pins upon the base member I22. At the bottom of the socket I26 there is provided a contact member I28 adapted to cooperate with the tip contact I25. The member I20 is connected to one lead of the power circuit. A metal ring member I20 is provided within the socket adapted to cooperate with the metal member I24 and connected to the other terminal of the power supply. In this embodiment also, the lamp I2I is readily inserted through the socket into operative relationship with other instrument members and is held firmly therein to obtain the advantages previously pointed out in connection with the other embodiments and, in addition, to obtain a simplified circuit connection means.

The various embodiments of the invention thus provide simple, relatively inexpensive, illuminat- The socket I06 is desirably formed as an.

ing means for an instrument. particularly adapted to airplane instruments, although adaptable to other instruments as well, in which the lamp bulb is inserted into and through a socket member to bring it into operative relationship with the instrument dial, and simultaneously is insertable by very simple means of such ruggedness and simplicity as to be readily operable under difilcult situations.

While there are above disclosed but a limited number or embodiments of the invention, it is possible to produce still other embodiments without departing from the inventive conbept herein disclosed, and it is therefore desired that only such limitations be imposed upon the appended claims as are stated therein or required by the prior art.

What is claimed and desired to be protected by United States Letters Patent is:

1. The combination with a lamp socket member having a passage therethrough; of a lamp and base assembly cooperating therewith, said assembly comprising a lamp bulb, a base having a finger grip portion and a pair of symmetrical engaging members attached to said base, the

- said socket member having interlocking members cooperating with the engaging members on said 'base to hold said bulb in place and simultaneously to complete an electric circuit thereto.

2. The combination with a lamp socket structure including a tubular passage having bayonet joint slots therein; of a lamp and base combination struicture cooperating therewith comprising a lamp bulb passable through said passage into said socket into illuminating relationship with a part to be illuminated; a base member attached to said bulb and enterable into said socket; said base member having a finger grip portion positioned outside of said socket; pin members attached to said-base and positioned cooperatively with the bayonet slots in said socket; and resilient contacts within said socket contacting with said pins.

3. In combinatiom'a lamp socket member having a rectangular passage therethrough; a rectangular base member enterable therein, said base member having a finger grip portion remaining outside said passage;, a lamp bulb attached to said base member; and pin members and locking spring members cooperating between said socket and said base member for holding said base within said socket.

4. In combination, a lamp socket member having a passage therethrough; a lamp bulb passable through said socket; a base for said lamp bulb attached thereto and having a finger grip portion; and spring members. within said socket rotatively engageable with said base for making connection to said bulb, and simultaneously hold ing said base in place.

5. In combination, a lamp socket member having a passage therethrough; a lamp bulb passable through said socket; a base for said lamp bulb attached thereto and having a finger srib portion; and spring members within said socket rotativeiy engaging with said base for making connection to said bulb and simultaneously holding said base in place, the said springs comprising a pair of arcuate members attached within said socket and a matching pair of arcuate members attached to said base.

' PAUL nor-mum. 

